Effect Of Iron Deficiency On Distortion Product Otoacoustic Emissions: An Experimental Study

Objective1 To explore the possible mechanism in which iron deficiency injures the haircell byobserving changes of DPOAE at different iron-deficient period in growing rats.2 To evaluate clinical application of DPOAE through the study of the effect of IDDPOAE.MethodsSixty-six healthy Wistar rats were randomly divided into the control and irondeficiency groups. The experimental models were prepared by iron-different diet.Eleven animals separately in each of the groups were examined by ABR,DPOAE andscanning electron microscopy.ResultsThe amplitudes of DPOAE was stable,and the scaning electron microscope showed nosigns of damages of the inner and outer hair cells in normal rats.The structure of innerand outer hair cells was cleare and eumorphism in the iron deficiency group,at thefourth week. The disarray,twisting and lodging were found in the outer haircell stereocilia at middle and base cochlear turns in the iron deficiency groupfrom the eighth week.. There was no significant difference in the ABR betweencontrol and experiment groups,but the average amplitude of DPOAE at middlefrequency was lower in the iron deficiency group at the fourth week. The findingsindicat that the chang of the amplitudes of DPOAE can be earlier than the change ofABR. The amplitudes of DPOAE in iron-deficient rats decreased significantly in 1-8KHz frequency (p<0.01) after Sweeks.The rate of threshold shift of ABR more than15dB was 36% and 45% separately at 8th and 12th week. And the amplitudes ofDPOAE was lower at high frequence from eighth week,but no significant change at12th week. The data suggest that the fuction of the outer hail cells is affected by irondeficiency for some degree. The functional and structural changes were found inthe iron deficiency rats.